1. Field of the Invention
The invention relates to a method for determining a characteristic status parameter of a memory unit by means of an electric circuit arrangement.
2. Description of the Prior Art
In such a method, as the characteristic status parameter, the aging status of the memory unit is determined by means of an electric circuit arrangement. The electric memory unit is a single electric memory cell or a plurality of memory cells electrically interconnected to one another, in particular an electric memory. This kind of electric memory is for example a rechargeable battery.
One problem with the use of batteries in stationary applications, such as in wind farms or in vehicles, such as hybrid or electric vehicles, is to determine the aging status of the individual memory cells (battery cells). The aging status is a characteristic status parameter of the memory cell and is estimated with adequate precision in a suitable way by determining the internal resistance of the individual memory units, in particular memory cells, by imposing currents of different frequency. This method is performed in validation and test environments using complicated laboratory equipment. For the purpose, the memory unit whose aging status is to be determined is stimulated with high-power current sources, and the internal resistance is determined by means of the voltage change ascertained via the individual memory units.